I understand how you are feeling with the sudden bleeding and worrying, and would like to share my experience with you. Hopefully it helps!

I had bleeding at 13 weeks, and was rushed to A&E at the hospital. I woke up at 3am suddenly bleeding a lot and it was scary!

But thankfully like your case, baby was still active in the scans. Doctor also checked that my cervix was still closed. Doctor at the hospital said it was a threatened miscarriage. I was given progesterone injections and progesterone pills to take twice a day to stabilize the pregnancy. I was told to rest as much as possible for the next week.

Afterwards I saw my regular Gynae (a fetal development specialist) and he said I had a slight placental abruption. Capillaries had broken causing the bleeding. He said that for a first time bleed it's ok, as baby will recover from it. Most importantly we had to prevent a second occurrence. I had the same thing where baby's growth was slightly slowed since the last scan, but baby's heart rate was going strong and doctor didn't seem too worried.

He continued to put me on progesterone injections for two more weeks along with progesterone pills to take twice a day. According to him if the brown blood continues to drain out its not an issue as it is old blood. During this time he has also instructed as much rest as possible and minimal walking. After the second week of progesterone injections, pills, and rest I am feeling stronger. Baby seems to be fine and in another weeks time doctor will reevaluate how much longer I need to rest and how much longer I need injections for.

Along with that, another friend of mine told me she had a similar situation and was put on bed rest. She has since given birth to a beautiful baby boy!

Try not to worry too much and focus on getting as much rest as possible and eating well!

How big was your subchorionic bleed and what happened?